Let AWS DNS API code pull creds from instance role

Add option (AWS_USE_INSTANCE_ROLE) to have the AWS DNS API driver pull
the necessary credentials from the AWS EC2 instance metadata endpoint
when required.

This is a non-breaking change as it only takes effect when explicitly
turned on via the environment variable, and fails safe back to the
normal code path.
This commit is contained in:
Mal Graty 2018-02-19 17:48:54 +00:00
parent 4a6b31fbe2
commit 48eaa0e5bf
1 changed files with 43 additions and 2 deletions

View File

@ -9,6 +9,7 @@
AWS_HOST="route53.amazonaws.com"
AWS_URL="https://$AWS_HOST"
AWS_METADATA_URL="http://169.254.169.254/latest/meta-data"
AWS_WIKI="https://github.com/Neilpang/acme.sh/wiki/How-to-use-Amazon-Route53-API"
@ -19,6 +20,10 @@ dns_aws_add() {
fulldomain=$1
txtvalue=$2
if [ -n "${AWS_USE_INSTANCE_ROLE:=$(_readaccountconf_mutable AWS_USE_INSTANCE_ROLE)}" ]; then
_use_instance_role
fi
AWS_ACCESS_KEY_ID="${AWS_ACCESS_KEY_ID:-$(_readaccountconf_mutable AWS_ACCESS_KEY_ID)}"
AWS_SECRET_ACCESS_KEY="${AWS_SECRET_ACCESS_KEY:-$(_readaccountconf_mutable AWS_SECRET_ACCESS_KEY)}"
if [ -z "$AWS_ACCESS_KEY_ID" ] || [ -z "$AWS_SECRET_ACCESS_KEY" ]; then
@ -30,8 +35,12 @@ dns_aws_add() {
fi
#save for future use
_saveaccountconf_mutable AWS_ACCESS_KEY_ID "$AWS_ACCESS_KEY_ID"
_saveaccountconf_mutable AWS_SECRET_ACCESS_KEY "$AWS_SECRET_ACCESS_KEY"
if [ -n "$AWS_USE_INSTANCE_ROLE" ]; then
_saveaccountconf_mutable AWS_USE_INSTANCE_ROLE "$AWS_USE_INSTANCE_ROLE"
else
_saveaccountconf_mutable AWS_ACCESS_KEY_ID "$AWS_ACCESS_KEY_ID"
_saveaccountconf_mutable AWS_SECRET_ACCESS_KEY "$AWS_SECRET_ACCESS_KEY"
fi
_debug "First detect the root zone"
if ! _get_root "$fulldomain"; then
@ -76,6 +85,10 @@ dns_aws_rm() {
fulldomain=$1
txtvalue=$2
if [ -n "${AWS_USE_INSTANCE_ROLE:=$(_readaccountconf_mutable AWS_USE_INSTANCE_ROLE)}" ]; then
_use_instance_role
fi
AWS_ACCESS_KEY_ID="${AWS_ACCESS_KEY_ID:-$(_readaccountconf_mutable AWS_ACCESS_KEY_ID)}"
AWS_SECRET_ACCESS_KEY="${AWS_SECRET_ACCESS_KEY:-$(_readaccountconf_mutable AWS_SECRET_ACCESS_KEY)}"
_debug "First detect the root zone"
@ -162,6 +175,34 @@ _get_root() {
return 1
}
_use_instance_role() {
if ! _get "$AWS_METADATA_URL/iam/security-credentials/" true | _head_n 1 | grep -Fq 200; then
_err "Unable to fetch IAM role from AWS instance metadata."
return
fi
_aws_role=$(_get "$AWS_METADATA_URL/iam/security-credentials/")
_debug "_aws_role" "$_aws_role"
_aws_creds="$(
_get "$AWS_METADATA_URL/iam/security-credentials/$_aws_role" \
| _normalizeJson \
| tr '{,}' '\n' \
| while read -r _line; do
_key="$(echo "${_line%%:*}" | tr -d '"')"
_value="${_line#*:}"
_debug3 "_key" "$_key"
_secure_debug3 "_value" "$_value"
case "$_key" in
AccessKeyId) echo "AWS_ACCESS_KEY_ID=$_value" ;;
SecretAccessKey) echo "AWS_SECRET_ACCESS_KEY=$_value" ;;
Token) echo "AWS_SESSION_TOKEN=$_value" ;;
esac
done \
| paste -sd' ' -
)"
_secure_debug "_aws_creds" "$_aws_creds"
eval "$_aws_creds"
}
#method uri qstr data
aws_rest() {
mtd="$1"